What does AggressiveOpts do with my timings?

Regina Anger regina.anger at hotmail.com
Sun Mar 30 14:43:25 PDT 2008

Hi Steve,

> This is likely a bug in the time caching feature introduced in b12 under 
> AggressiveOpts.  You can confirm this by running with 
> "-XX:+AggressiveOpts -XX:-CacheTimeMillis" and see if the problem goes 
> away.  There is an interaction between time caching, counted loops with 
> the server compiler, and biased locking, that can make time offsets go 
> squirrelly around 4 seconds (or BiasedLockingStartupDelay) into the 
> run.  It should go away around b26, when time caching will be removed.

Of course you were right, disabling time caching gave me stable results.
Sad that timecaching seems to not work out as expected, I for myself also had scalability problems in some code which did a lot of System.currTimeMillis() in a lock ;)


PS: Your blog is really interesting - both the airplane and of course also the compiler stuff. Thanks for writing those interesting articles.
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